The USA has a policy of not invading local countries, because they're too close to home. So, its mostly power projection "fighting them over there, so we don't have to fight them .. here".

Really, this is a fundamental issue to understand. USA is not a peace-bringing nation - it is a war-projection nation. In the same way that one can use fire to fight fires, the USA thinks its war-making is actually bringing peace to the world.

I know - it doesn't make any sense. But, the military-industrial complex which runs the USA doesn't care if you think it makes sense. It only cares about dropping bombs, clearing the shelves of inventory with short half lives, and replacing it with new inventory.

EDIT: the claim that USA's wars are "just, righteous wars" is highly specious and, frankly, risible. The USA has toppled more democratically elected officials than any other nation in the history of mankind. I urge you to consider the hubris of the statement: "the USA only fights good wars", because there is fiction, and there is fact.

The fact is, a lot of people in democratic societies around the world feel that the USA hasn't fought a good war since WW2, and in fact that the opposite is true: the USA fights to put its own dictators into power. Even a casual investigation of this fact yields more than enough evidence to support the statement: the USA is up to no good.